US Attorney General John Ashcroft announced the release of a report by the Dept. of Justice Task Force on Intellectual Property at the Tech Museum on 10/13/04 in San Jose, CA.

Photo: Paul Chinn, The Chronicle

US Attorney General John Ashcroft announced the release of a report...

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FILE - In this Thursday, June 26, 2008 photo, John Yoo, a law professor at the University of California at Berkeley, testifies on Capitol Hill in Washington. Former Justice Department lawyers Jay Bybee and John Yoo showed "poor judgment" but did not commit professional misconduct when they authorized CIA interrogators to use waterboarding and other harsh tactics at the height of the U.S. war on terrorism, an internal review released Friday, Feb. 19, 2010 found.

John Yoo, the UC Berkeley law professor whose liability for allegedly authorizing torture during the Bush administration has been under federal appeals court review for more than a year, has some new legal ammunition - a Supreme Court ruling dismissing a former detainee's suit against Yoo's onetime boss, then-Attorney General John Ashcroft.

The Ninth U.S. Circuit Court of Appeals in San Francisco asked lawyers for Yoo and inmate Jose Padilla about the implications of the court's May 31 ruling shielding Ashcroft from a suit by a man he had ordered detained as a "material witness," allegedly on a pretext.

Yoo is appealing a judge's ruling allowing Padilla to sue him for actions as a Justice Department lawyer that allegedly led to Padilla's detention and brutal treatment in a Navy brig. The Ninth Circuit heard arguments on that appeal in June 2010.

During nearly four years in the brig, Padilla said, he was shackled in stress positions, deprived of sleep, kept in darkness and blinding light for lengthy periods, and threatened with death. Initially accused of conspiring with al Qaeda to detonate a radioactive "dirty bomb," he was later convicted of unrelated charges of aiding terrorists and sentenced to 17 years in prison.

Yoo, a government lawyer from 2001 to 2003, wrote memos broadly interpreting presidential authority over interrogation and detention and saying the president may have the power to authorize torture. Padilla's suit said Yoo personally approved his detention and treatment in the brig.

The Supreme Court case involved Abdullah al-Kidd, who was arrested in 2003, shackled and held for two weeks as a material witness in a terrorism case but was never called to testify.

The justices were divided over whether use of the witness law as a pretext for detention is illegal, but ruled unanimously that Ashcroft was immune from being sued as a federal official because he did not violate any rights that were clearly established.

Yoo's lawyer said the same reasoning applies to his case.

Even if Padilla's arrest and treatment in the brig could be traced to Yoo's actions as a lawyer, he can't be held responsible for violating the rights of an "enemy combatant" - the status President George W. Bush assigned to Padilla - because the courts have never defined those rights, said Yoo's attorney, Miguel Estrada.

"It was not clearly established between 2001 and 2003 that a citizen enemy combatant is entitled to the same constitutional rights as an ordinary prisoner," Estrada told the appeals court.

But Jonathan Freiman, a lawyer for Padilla, said his case is different because torture in custody is clearly illegal.

"Our most basic rights may not be undone by the unilateral decision of the executive (to classify Padilla as a combatant) and the secret legal opinion of a top-level government lawyer," Freiman told the court.